diff --git a/Lib/test/test_warnings/__init__.py b/Lib/test/test_warnings/__init__.py
index 9f1cd7574f5..42c76035c38 100644
--- a/Lib/test/test_warnings/__init__.py
+++ b/Lib/test/test_warnings/__init__.py
@@ -1007,12 +1007,12 @@ def test_late_resource_warning(self):
         # don't import the warnings module
         # (_warnings will try to import it)
         code = "f = open(%a)" % __file__
-        rc, out, err = assert_python_ok("-c", code)
+        rc, out, err = assert_python_ok("-Wd", "-c", code)
         self.assertTrue(err.startswith(expected), ascii(err))
 
         # import the warnings module
         code = "import warnings; f = open(%a)" % __file__
-        rc, out, err = assert_python_ok("-c", code)
+        rc, out, err = assert_python_ok("-Wd", "-c", code)
         self.assertTrue(err.startswith(expected), ascii(err))